Jiang-Ming Yang Rui Cai Yida Wang Jun Zhu Lei Zhang Wei-Ying Ma Incorporating site-level knowledge to extract structured data from web forums. 181-190 2009 WWW http://doi.acm.org/10.1145/1526709.1526735 conf/www/2009 db/conf/www/www2009.html#YangCWZZM09